Nano Pd-Fe 3 O beads: as an efficient and magnetically separable catalyst for Suzuki, Heck and Buchwald Hartwig coupling reactions

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1 Electronic Supplementary Material (ESI) for RSC Advances. This journal is The Royal Society of Chemistry Supplementary Information for ano Pd-Fe 3 beads: as an efficient and magnetically separable catalyst for Suzuki, Heck and Buchwald Hartwig coupling reactions Radheshyam S. Shelkar, Sitaram H. Gund, Jayashree M. agarkar* Department of Chemistry, Institute of Chemical Technology, Matunga, Mumbai , India. *Corresponding author. Tel.: /2222; fax: jm.nagarkar@ictmumbai.edu.in Experimental section Materials All reagents were of analytical grade, purchased from M/S S. D. Fine Chemicals Pvt. Ltd. and used without further purification. All products were characterized by MS analysis (GC-MS Shimadzu QP 2010) and 1 H MR (300 MHz, CDCl 3 ). S1. Synthesis of palladium nanoparticles Pd(Ac) 2 (200 mg) was added into (PEG) (16 g of PEG- 600). The resulting light yellow colored homogeneous solution was stirred on a magnetic stirrer at 80 C for 3h. The solution slowly turned from light yellow to dark grey, signifying the formation of Pd Ps. The PEG stabilized Pd particles were then allowed to cool at room temperature. The as synthesized Pd species were then dispersed in dry ethanol under sonication. The dispersion was subjected to centrifuge at 13,000 rpm at room temperature (25 C). The separated particles were washed properly with ethanol and dried under vacuum for further use.

2 2 S2. Synthesis of Pd-Fe 3 4 magnetic nanocomposite (Pd Fe 3 4 MPs) The Pd incorporated Fe 3 4 nanoparticles were prepared by adding Pd Ps in to the reaction mixture of Fe 3 4. The Fe 3 4 Ps were prepared by sonochemical assisted co-precipitation method. The FeCl 3.6H 2 (2.70g) and urea (1.8 g) were dissolved in water (100 ml) at 80 0 C for 2h. to get brown colored solution. To the resultant reaction mixture cooled to room temperature was added FeS 4.7H 2 (1.39g) and then 0.1M ah until ph-10. The mixture was subjected to ultrasonication (frequency 30 khz and power of 150 Watts). The temperature of the bath was maintained at 60 C and maintained for 30 min in air atmosphere. To this precipitate, the dispersion of the as-synthesized Pd Ps in ethanol was slowly added with continuous stirring. After addition of Pd Ps the reaction mixture changed from brown to chocolate brown colored precipitate. The reaction temperature was slowly brought to 80 C, maintained for 1h and then aged overnight at room temperature. The chocolate brown colored precipitate was then separated by filtration, washed several times with distilled water and finally with ethanol. The solid product was then further dried in an oven at 100 C for nearly two hour and finally calcined at 200 C for 4h. The synthesized sample by this method was denoted as Pd-Fe 3 4 MPs. S3. Synthesis of magnetic beads of nano Pd Fe 3 An aqueous Pd-Fe 3 4 MPs suspension was first prepared by taking 2g of Pd-Fe 3 4 nano powder into 10mL distilled water, followed by sonication for about 30 min. Preparation of beads was then accomplished by mixing of 5mL of the Pd-Fe 3 4 suspension with 20 ml of 4% (w/w) sodium alginate solution, kneading the mixture for 2h by a high speed agitator and dropwise injection of the obtained sol into 0.1 mol/l CaCl 2 solution through a 0.5 mm medical needle to form beads. The formed beads were gently stirred in the CaCl 2 solution for an additional 3h to harden and then they were thrice washed with distilled water followed by drying at 40 0 C for

3 3 overnight. The obtained beads were calcined at C for 3h and the above prepared beads referred as beads of nano Pd Fe 3 Fig. S1 FT-IR Spectra of Fe 3 4, Pd-Fe 3 4 and Pd-Fe 3 Pd(Ac)2 Pd(0) Soln after 3h. Pd(0) Soln after 30days. Pd-Fe34@Alg. Soln after 30days. Fig. S2 UV-Visible absorption spectrum of Pd-Fe 3

4 4 Fig. S3 Thermogravimetric curve for Pd-Fe 3 Fig. S4 2 isotherms curve for Pd-Fe 3

5 5 Fig. S5 Pore size curve of the Pd-Fe 3 Fig. S6 XRD of recycled catalyst after fifth cycle.

6 6 S4. General experimental procedure for Suzuki cross coupling reactions catalyzed by beads of nano Pd Fe 3 Aryl halide (1.0 mmol), boronic acids (1.5 mmol), 2 mmol K 2 C 3 and 2 mg of nano Pd Fe 3 catalyst were added in a1 ml water and the reaction was carried at 80 ºC for 1.5 4h. The progress of the reaction was monitored by Gas Chromatography (GC). After completion of reaction, the reaction mixture was cooled to room temperature and it was extracted with ethyl acetate. The beads of catalyst were easily recovered by simple filtration or by magnetic separation followed by washing with ethanol and drying and preserved for next runs. The pure products were obtained by column chromatography using pet ether: ethyl acetate as the eluent. The preserved catalyst reused in a subsequent run for recyclability study. The conversion of reactant was determined by Gas chromatography (GC). The products were characterized by GC- MS and 1 HMR. (Table 2, entry 1) White solid, M.p C, 1 H-MR (300 MHz, CDCl 3 ): δ = (m, 4H), (m, 4H), (m, 2H). (Table 2, entry 2) White solid, M.p C, 1 H-MR (300 MHz, CDCl 3 ): δ = 7.56 (t, 2H), 7.45 (t, 2H), 7.34 (d, 2H), 7.26 (d, 1H), 6.99 (d, 2H), 3.87 (s, 3H). (Table 2, entry 3) Colorless solid, M.p C, 1 H-MR (300 MHz, CDCl 3 ): δ = 8.29 (s, 1H), 7.59 (d, 2H), 7.53 (d, 2H), (m, 2H), (m, 1H), 6.93 (d, 2H). (Table 2, entry 9) White solid, M.p C, 1 H-MR (300 MHz, CDCl 3 ): δ = 8.05 (d, 2H), (m, 4H), (m, 3H), 2.64 (s, 3H). Table S1. Comparison between some reported works and the present work for Suzuki coupling reaction of iodobenzene and phenyl boronic acid. Entry Catalyst Reaction Conditions Yield (%) Reference 1. Carbon nanocomposite Pd DMF/H 2, K 2 C 3, 100 C, 1.5h Pd/C Ps DMF, Et 3, 140 C, 2h. 98 2

7 7 3. Pd-P-300 EtH/H 2, a 2 C 3, TBAB, 55 C, h. 4. G-Pd@Ag-AgBr EtH/H 2, K 2 C 3, 2 atm., 300W 97 4 Xe lamp, 25 C, 0.5h. 5. Pd Ps IPA, K 2 C 3, 100 C, 20h Au/Pd Ps EtH/H 2, K 2 C 3, 2 atm., 80 C, h. 7. SBA-15-EDTA-Pd DMF, K 2 C 3, 120 C, 5h Pd Ps/ PS DMF/H2, a 2 C 3, 100 C, 12h G-H 2 -Pd EtH/H 2, K 2 C 3, 60 C, 0.5h Fe Pd IPA, K 2 C 3, 80 C, 6h ano Pd Fe 3 H 2, K 2 C 3, 80 C, 1.5h. 97 Present Work S5. General experimental procedure for Heck cross coupling reactions catalyzed by beads of nano Pd Fe 3 Aryl halide (1.0 mmol), olefins (2 mmol), 2 mmol Et 3 and 4 mg of nano Pd Fe 3 catalyst were added in a1 ml water and the reaction was carried at 85 ºC for 3 8h. The progress of the reaction was monitored by Gas Chromatography (GC). After completion of reaction, the reaction mixture was cooled to room temperature and it was extracted with ethyl acetate. The beads of catalyst were easily recovered by simple filtration or by magnetic separation followed by washing with ethanol and drying and preserved for next runs. The pure products were obtained by column chromatography using pet ether: ethyl acetate as the eluent. The preserved catalyst reused in a

8 8 subsequent run for recyclability study. The conversion of reactant was determined by Gas chromatography (GC). The products were characterized by GC-MS and 1 HMR. (Table 4, entry 1) Colorless liquid, 1 H-MR (600 MHz, CDCl 3 ): δ = 7.68 (d, J = 16.0 Hz, 1H), (m, 2H), (m, 3H), 6.44 (d, J = 16.0 Hz, 1H), 4.27 (q, J = 7.1 Hz, 2H), 1.32 (t, J = 7.1 Hz, 3H). (Table 4, entry 5) White solid, M.p C, 1 H-MR (300 MHz, CDCl 3 ): δ = 8.25 (d, 2H, J = 8.8 Hz), (m, 3H), 6.56 (d, 1H, J = 16.1 Hz), 4.29 (q, 2H, J = 7.1 Hz), 1.28 (q, 3H, J = 7.1 Hz). (Table 4, entry 12) Colorless liquid, 1 H-MR (600 MHz, CDCl 3 ): δ = 7.68 (d, J = 16.2 Hz, 1H), (m, 2H), (m, 3H), 6.44 (d, J = 16.2 Hz, 1H), 3.79 (s, 3H). (Table 4, entry 16) White solid, M.p C, 1 H-MR (300 MHz, CDCl 3 ): δ = 7.54 (d, J = 7.2 Hz, 4H), (m, 6H), 7.14 (s, 2H). S6. General experimental procedure for Buchwald-Hartwig amination reactions catalyzed by beads of nano Pd Fe 3 Aryl halide (1.0 mmol), secondary amines (1.5 mmol), 2 mmol t Bua and 2 mg of nano Pd Fe 3 catalyst were added in a 1 ml DMS and the reaction was carried at 110ºC for 12h. The progress of the reaction was monitored by Gas Chromatography (GC). After completion of reaction, the reaction mixture was cooled to room temperature and it was extracted with ethyl acetate. The beads of catalyst were easily recovered by simple filtration or by magnetic separation followed by washing with ethanol and drying and preserved for next runs. The pure products were obtained by column chromatography using hexane: ethyl acetate as the eluent. The preserved catalyst reused in a subsequent run for recyclability study. The conversion of reactant was determined by Gas chromatography (GC). The products were characterized by GC-MS and 1 HMR. (Table 6, entry 1) 1 H-MR (600 MHz, CDCl 3 ): δ = (m, 2H), (m, 3H), 3.86 (t, J = 4.8 Hz, 4H), 3.16 (t, J = 4.8 Hz, 4H).

9 9 Table S2. The comparison of activities of reported Pd-Fe 3 catalyst with conventional Pd/C catalyst. Entry Reaction GC Yield (%) Commercial Pd/C Pd-Fe 3 1. Suzuki reaction a Heck reaction b Buchwald Hartwig reaction c a Reaction Conditions: Iodobenzene (1 mmol), phenylboronic acids (1.5 mmol), K 2 C 3 (2 mmol), Catalyst (0.05 mol%), Water (1 ml) at 80 C for 1.5h. b Reaction conditions: Iodobenzene (1 mmol), Ethylacrylate (2 mmol), Et 3 (2 mmol), Catalyst (0.1 mol%), Water (1 ml) at 85 C for 3h. c Reaction conditions: Iodobenzene (1 mmol), Morpholine (1 mmol), t Bua (1 mmol), Catalyst (0.05 mol%), DMS (1 ml) at 110 C for 12h. Table S2 shows that nano Pd-Fe34@Alg is also superior to commercial Pd/C. We carried out Suzuki, Heck and Buchwald Hartwig amination reaction with commercial Pd/C under the same optimized reaction conditions. The commercial Pd/C gives only 33% and 65% yield of the product for Suzuki and Buchwald Hartwig amination reactions respectively. The commercial Pd/C does not showed any activity for Heck reaction under the optimized conditions.

10 10 S7. Characterization of products by mass spectra (EI, 70 ev): (a) Suzuki coupling products. 1. (Table 2, entry 1) MS (m/z/rel.int.): 154(M + ): 51(8.1), 76(26.5), 154(100). 2. (Table 2, entry 2 ) H 3 C MS (m/z/rel.int.): 184(M + ): 51(4.0), 76(7.5), 115(33.7), 141(47.9),169(53.5), 184(100).

11 11 3. (Table 2, entry 4). MS (m/z/rel.int.): 168(M + ): 51(6.8), 83(17.5), 153(49.1), 167(92.3),168(100). 4. (Table 2, entry 5) 2 MS (m/z/rel.int.): 199(M + ): 51(12.0), 76(17.9), 152(99.5), 169(36.7),199(100).

12 12 5. (Table 2, entry 7) H MS (m/z/rel.int.): 170(M + ): 51(3.8), 115(17.9), 141(25.9), 170(100). 6. (Table 2, entry 8) MS (m/z/rel.int.): 168(M + ): 51(4.1), 83(9.8), 152(23.6), 168(100).

13 13 7. (Table 2, entry 9). H 3 CC MS (m/z/rel.int.): 196(M + ): 43(11.6), 76(20.3), 152(58.2), 181(100),196(52.7). 8. (Table 2, entry 10). C MS (m/z/rel.int.): 179(M + ): 51(5.3), 76(12.6), 151(16.7), 179(100).

14 14 9. (Table 2, entry 11). F MS (m/z/rel.int.): 172(M + ): 51(4.0), 76(5.4), 85(10.6), 152(4.6),172(100). 10. (Table 2, entry 15). MS (m/z/rel.int.): 155(M + ): 51(16.8), 77(20.8), 127(19.0), 155(100).

15 (Table 2, entry 16). S MS (m/z/rel.int.): 160(M + ): 51(5.9), 115(39.5), 128(14.9), 160(100). 12. (Table 2, entry 17). MS (m/z/rel.int.): 182(M + ): 51(5.1), 76(7.9), 152(16.1), 167(59.2),182(100).

16 (Table 2, entry 18). F MS (m/z/rel.int.): 172(M + ): 51(4.5), 85(10.1), 172(100). (b)heck coupling products. 1. (Table 4, entry 1). MS (m/z/rel.int.): 176(M + ): 51(18.6), 77(37.1), 103(54.2), 131(100),176(28.7).

17 17 2. (Table 4, entry 2). H 3 C MS (m/z/rel.int.): 206(M + ): 51(5.9), 77(16.5), 134(56.9), 161(100),206(71.2). 3. (Table 4, entry 3). H 2 MS (m/z/rel.int.): 191(M + ): 59(20.1), 91(30.3), 119(72.2), 146(100),191(90.1).

18 18 4. (Table 4, entry 4). H 5. (Table 4, entry 5). 2

19 19 6. (Table 4, entry 11). S MS (m/z/rel.int.): 182(M + ): 45(11.1), 65(29.1), 109(42.6), 137(100),182(48.7). 7. (Table 4, entry 12). MS (m/z/rel.int.): 162(M + ): 51(27.2), 77(43.5), 103(70.0),131(100), 162(50.6).

20 20 8. (Table 4, entry 13). MS (m/z/rel.int.): 176(M + ): 51(9.6), 91(30.7), 115(93.8), 145(100),176(32.9). 9. (Table 4, entry 14). H 3 CC MS (m/z/rel.int.): 204(M + ): 43(40.1), 102(19.1), 189(100), 204(32.6).

21 (Table 4, entry 15). H MS (m/z/rel.int.): 147(M + ): 51(38.5),77(47.8), 103(58.9), 147(100). 11. (Table 4, entry 16). MS (m/z/rel.int.): 180(M + ): 51(11.6), 76(20.9), 89(28.3), 165(51.3),180(100).

22 22 (c) Buchwald Hartwig amination reaction products. 1. (Table 6, entry 1). MS (m/z/rel.int.): 163(M + ): 51(13.5), 77(31.8), 105(100), 163(55.7). 2. (Table 6, entry 2). H 3 C

23 23 3. (Table 6, entry 3). 2 MS (m/z/rel.int.): 208(M + ): 51(13.3), 77(30.0), 120(43.7), 150(100), 208(77.5). 4. (Table 6, entry 4). MS (m/z/rel.int.): 177(M + ): 51(5.7), 65(17.1), 91(26.4), 118(100), 177(60.6).

24 24 5. (Table 6, entry 5). MS (m/z/rel.int.): 213(M + ): 51(3.4), 77(16.5), 127(39.0), 155(100), 213(76.8). 6. (Table 6, entry 6). MS (m/z/rel.int.): 177(M + ): 77(9.3), 91(35.8),119(100), 177(58.0).

25 25 7. (Table 6, entry 7). F MS (m/z/rel.int.): 181(M + ): 51(5.5), 75(14.7), 95(27.3), 123(100), 181(52.0). 8. (Table 6, entry 10). 2 MS (m/z/rel.int.): 208(M + ): 51(45.2), 77(100), 105(60.9),119(85.3), 191(73.0), 208(48.0).

26 26 9. (Table 6, entry 11). MS (m/z/rel.int.): 163(M + ): 57(21.8), 77(37.6), 105(100),163(54.2). 10. (Table 6, entry 12). MS (m/z/rel.int.): 164(M + ): 51(19.2), 79(100), 107(35.7), 133(47.0), 164(32.3).

27 (Table 6, entry 13). MS (m/z/rel.int.): 160(M + ): 51(15.1), 77(39.7), 105(37.5), 160(100). 12. (Table 6, entry 14). MS (m/z/rel.int.): 176(M + ): 43(100), 71(49.5), 105(64.5), 176(91.9).

28 (Table 6, entry 15). MS (m/z/rel.int.): 238(M + ): 51(12.6), 77(42.9), 105(100), 132(56.3), 238(78.4). 14. (Table 6, entry 16). MS (m/z/rel.int.): 189(M + ): 77(12.0), 106(100), 189(13.5).

29 (Table 6, entry 17). MS (m/z/rel.int.): 183(M + ): 51(23.7), 77(46.3), 104(30.1), 167(29.4), 183(100). 16. (Table 6, entry 18). MS (m/z/rel.int.): 273(M + ): 51(7.3), 77(22.5), 91(100), 182(20.2), 273(42.4).

30 (Table 6, entry 19). MS (m/z/rel.int.): 149(M + ): 51(11.1), 77(30.1), 106(52.3), 134(100), 149(30.7). 18. (Table 6, entry 20). MS (m/z/rel.int.): 173(M + ): 51(25.5), 77(90.5), 104(100),144(35.8), 158(88.7), 173(56.2).

31 31 S8. Characterization of some products by 1H MR spectra (300/600 MHz, CDCl3): 1. (Table 2, entry 1). 2. (Table 2, entry 2). H3C

32 32 3. (Table 2, entry 3). H 4. (Table 2, entry 9). H3CC

33 33 5. (Table 4, entry 1). 6. (Table 4, entry 5). 2

34 34 7. (Table 4, entry 12). 8. (Table 4, entry 16).

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